Interesting article on NVM (Non Volatile Memory) – this is non volatile RAM you can plug into a memory DIMM. It is about 1000 times faster than an SSD and byte addressable, also the expectation is that the size will be huge – TBs. To access full performance you have to by pass the OS page cache etc (OS and DB are designed for slow disks) using DAX, https://www.kernel.org/doc/Documentation/filesystems/dax.txt. The paper also has a nice introduction to Write Ahead Logging (WAL) which is used in nearly all databases, http://www.vldb.org/pvldb/vol10/p337-arulraj.pdf